The present invention relates to an upper roller feeding mechanism for a sewing machine and more particularly to an upper roller feeding mechanism mounted on the machine in operative association with the well known type of feed dog mechanism disposed beneath the machine's presser foot.
Conventional sewing machines which utilize an upper feeding mechanism have a roller that is supported by the machine's presser mechanism and is driven intermittently by a plurality of operatively connected elements which includes a drive chain for effecting actuation of said roller. The mechanism requires, what is considered, an excessive amount of space to perform its intended function due to the fact that some of the elements are housed within the frame of the machine and others are mounted on the outer surface thereof.
Additionally, the drive chain which is adapted to actuate the roller is rather long which creates a problem of back lash that is effective in causing a delay in the intended movement of the upper feeding mechanism relative to the lower one.
During the stitching operation of joining two or more layers of fabric such a delay will cause relative sliding or slipping between the layers and as intended said layers will not be displaced simultaneously by the stitching instrumentalities.
Due to the fact that many of the elements of the drive are disposed on the outer surface of the sewing machine frame, a serious problem presents itself of providing the necessary amount of lubricant for each of said elements.
An object of the present invention is to eliminate the problems described above with known types of drives by providing a drive for the upper feed roller which requires substantially less space in the sewing machine and in which the various components thereof are arranged so as to simplify their lubrication.